Fire extinguishing apparatus



Aug. 11, 1931. D. MAPES FIRE EXTINGUISHING APPARATUS Filed July 19. 1928 awwwntoz 2 7 Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE DANIEL MAPES, 0F MAMARONECK, NEW YORK, ASSIGNOR TO WALTER KIDDE & COM- PANY, INCL, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK FIRE EXTINGUISHING APPARATUS Application filed July 19,

This invention has to do with the painting or enameling of parts of automobiles and other machines which are commonly painted or enameled bypassing the same on a con veyor through a tank, called a dip tank, which contains the paint or enamel, the parts being conveyed thence to a drying or baking oven. The paint or enamel employed is highly inflammable and means are provided whereby a fire extinguishing medium, such as carbonic acid gas, can be delivered under the surface of the liquid in the tank in the event of the outbreak of fire. The fire extinguishing medium is delivered through pipes from a source of supply from which it is released on the outbreak of fire and frequently means are also provided whereby the fire extinguishing medium is also delivered into the room in which the paint or enameling takes place. The dis charge of the fire extinguishing medium is usually controlled at a point near the source of supply and the pipes through which it is delivered are full of atmospheric air until it is displaced by the fire extinguishing medium. The paint or enamel used is subject to oxidation in the presence of air and it has sometimes happened heretofore that the surface of the liquid within the pipe through which it is delivered to the tank and in which it stands, perhaps for a long time, at the level of the liquid in the tank and therefore exposed to the oxidizing effect of the considerable volume of air contained in the delivery pipe or pipes between the tank and the source of supply of the fire extinguishing medium, becomes oxidized and therefore hardened and encrusted at the surface, to such an extent that the free flow of the fire extinguishing medium is prevented or retarded.

The object of this invention is to prevent such clogging of the delivery pipe and for that purpose a stop which will yield or give way readily to the pressure of the fire extinguishing medium is placed in the delivery pipe at a point in proximity to the enamel tank so that the contact of air with the paint or enamel, except in such small volume that it can have no appreciable oxidizing effect, is prevented. Preferably the stop employed is a readily frangible disc which completely 1928. Seri'aI No. 293,823.

shuts off air but will be ruptured by the pressure of the fire extinguishing medium when it is admitted to the delivery pipe.

The invention will be more fully explained hereinafter with reference to the accompanying drawings in which:

Figure 1 is a view in sectional elevation showing a dip tank of ordinary construction provided with a pipe for the delivery of a fire extinguishing medium below the surface of the paint or enamel in the tank.

Figure 2 is a detail view, partly in section, showing a coupling arranged to support a frangible disc in the delivery pipe.

The dip tank a, of any suitable dimensions, is adapted to receive a body of paint or enamel, the upper surface of which is indicated at M. lVithin the tank, below the usual level of the surface of the liquid therein, is placed a delivery pipe Z2 which may be provided with cross-arms, as at 6 and, at its end, a T 5 this pipe system being freely vented at its ends for the delivery within the body of the liquid of the fire extinguishing medium, such as carbonic acid gas, which may be supplied from any convenient source, through a supply pipe indicated in part at c. Interposed in the supply pipe or between the supply pipe and the delivery pipe, at a point in close proximity to the tanka, preferably below or near to the usual level of the surface of the liquid in the tank, is a stop which prevents communication between the delivery pipe and the atmosphere, except for such relatively small volume of air as may be trapped close to the stop. In the preferred construction illustrated in the drawings a coupling (Z is interposed between the supply pipe and the delivery pipe in close proximity to the tank which coupling is adapted to support a readily frangible disc 6. In the construction shown the frangible disc e is supported upon a shoulder (Z of the coupling, being held in place thereon by a bushing f. The coupling d may be provided with a clean-out opening (Z closed by a removable cap (Z Under ordinary conditions the paint or enamel in the tank a fills the delivery pipe to a point quite close to the frangible disc 6, so that the volume of air trapped between the paint or enamel in the delivery pipe and the frangible disc is not sufficient to produce oxidation of the liquid such as to form a crust on its surface. The frangible disc, under ordinary conditions, is subject only to atmospheric pressure, under which it does not give way. In the event of the outbreak of fire, however, the frangible disc is ruptured by the pressure of the lire extinguishing medium admitted to the pipes and then ofiers no obstruction to the free flow thereof.

It will be understood that the construction and arrangement of the stop which protects the liquid in the delivery pipe from contact with any substantial volume of air may be varied to suit different conditions of use and that the invention, therefore, is not restricted to the particular construction and arrange ment shown and described herein except as pointed out in the claims.

Vhile the invention has been described with particular reference to its use in connection with tanks used in the enameling or painting of articles, it will be understood that the invention is capable of advantageous use with tanks for the storage or preparation of inflammable or oxidizing liquids.

I claim as my invention 1. The combination with a. tank to contain an inflammable and oxidizible liquid, a supply and delivery pipe freely vented at its delivery end for delivering fire extinguishing medium within the body of the liquid in the tank, and a stop interposed in the pipe in close proximity to the liquid in the pipe for minimizing the quantity of air in the pipe in contact with the liquid and readily yieldable under the pressure of the fire extinguishing medium.

2. The combination with a tank to contain an inflammable and oxidizable liquid, a supply and delivery pipe freely vented at its delivery end for delivering lire extinguishing medium within the body of the liquid in the tank, a stop interposed in the pipe in close proximity to the liquid in the pipe for minimizing the quantity of air in the pipe in contact with the liquid and readily yieldable under the pressure of the fire extinguishing medium, and a clean out connection adjacent the stop to permit the delivery pipe to be cleaned.

This specification signed this 10th day of July A. D. 1928.

DANIEL MAPES. 

